Who was the man calling his name?
This was the man who had forced his way up to the front on the crowd and didn't care who he offended
Then he kept staring at Robin creepily while he was saying his vows to Andras on their wedding day.
What Robin didn't know was...
This was also the man who stalked him to his room after screwing over the cabin boy both literally and figuratively.
He would have done the same to Robin if it wasn't for the enchanted wards that Andras had Oceanus set up around their cabin.
For this man was pretending to be a sailor and wasn't human.
As the other kind, his true self would be revealed if he came anywhere near those wards.
So he became even more determined to lure Robin out of the cabin.
Just by chance he was spotted by the traitor and offered an opportunity too good to resist.
The sailor recognized the man who proudly sat at the table of the inner circle so he had no reason to doubt this gentleman fae's credibility.